The consumption of ready-to-eat pizzas has increased in the last years because of the handiness of the product, its low cost, good flavour and nutritional value. However, ready-to-eat pizzas undergo intense manipulation during processing, contributing to spoilage, reducing the quality and increasing the risks of contamination by pathogens. Besides convenient products, consumers also seek for safer foods, with increasing demand for the use of natural compounds as food preservatives. Among them, the oregano essential oil presents antimicrobial activity and it is a spice used in the cookery of several countries. The objective of this work was to develop a cellulosic film incorporated with oregano essential oil for the conservation of refrigerated ready-to-eat pizza. The oregano essential oil incorporated to the film, in the concentrations of 25% and 50% w/w, showed in vitro inhibitory effect against Penicillium spp., and Staphylococcus aureus. When the oil was applied to the pizza, it caused a decrease in the compounds ñ-cymene and ã-terpinene and a consequent increase in tymol and carvacrol concentrations; however, in an amount probably not enough for the inhibitory effect against microorganisms. The mechanical resistance of the films incorporated with 25% and 50% of oregano essential oil was reduced, and film tenacity increased by 50% compared with the control (0%). The use of films incorporated with oregano essential oil for pizza packaging is of great interest, since the oregano is already an ingredient of the product and therefore it does not compromise the flavour and aroma of the product.
active packaging; antimicrobial effect; foods; natural preservative.
